Physical Properties
Alkali Metals
Lindsay Ellsworth, Kristin Ellsworth,
Meghan Winer, Emilie Puttrich
Inorganic Chemistry
Dr. Clark
April 13, 2005
Chemical Properties
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M+ cation
Electron configuration ns1
Ionic bonding
Largest atomic radii in their
period
• Low electronegativity
• Low 1st ionizaton energy
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Soft
Low melting temperature
Low boiling temperature
Low density
High conductivity
Ionic radii << atomic radii
Body-centered cubic lattice
Flame colors
Li
Na
K
Rb
http://www.uhh.hawaii.edu/~kenho
n/mineralogy/course-syllabus/xtallattice/bristol-bravais1.htm
Cs
Fr
Reactivity
• Very reactive (low 1st ionization energy)
• Reactivity increases from Li to Fr
2 Cs(s) + 2 H2O(l) → 2 CsOH(aq) + H2(g) (in phenolphthalein indicator)
– M → M+ + e– ↓ from Li to Fr
– No M2+ due to high 2nd ionization
energy
• Enthalpy ↓ from Li to Fr
• Reducing agents: large and
negative standard potential of
M+/M
http://intro.chem.okstate.edu/ChemSo
urce/Alkalimetals/alkmetal8a.htm
http://jchemed.chem.wisc.edu/jcesoft/cca/CCA4/M
AINPT/CmCz_elt/Cs.HTM
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First Row Anomaly: Lithium
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Lithium
3
Li
[6.94]
High covalent bonding character
Most solvated
Lowest density
High negative standard potential
High BP and MP
Reactivity
Na+/K+ Channel
• Found in cellular plasma
membrane
• Ion channel
• Participates in secondary
active transport systems
• Applications
– Osmotically controls the water
content of cells
– Regulates the electrical
excitability of nerve cells
– Imports nutrients into the cell
and exports waste out of the
cell
– Normal oxides
4Li(s) + O2(g) Æ 2Li2O (s)
– Nitride
6Li(s) + N2(g) Æ 2Li3N(s)
http://www.cvphysiology.com/Arrh
ythmias/A007_Na-K_pump.gif
http://nobel.scas.bcit.ca/resource/ptable/li.htm
Na+/K+ Channels
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Antiporter
3Na+(in)+2K+(out)+ATP+H2O
3Na+(out)+2K+(in)+ADP+Pi
Na+ out of cell, K+ into cell
Electrochemical Gradient
http://www.ttuhsc.edu/SOM/phy
siology/Figures/s_NaKATPase.gif
http://www2.kenyon.edu/Depts/BioEllip
se/courses/biol105/html/cell.jpg
Lithium Batteries
• high energy,
lightweight
• useful for low current,
long lasting appliances
• Three types of Li
batteries
– LiCoO2 -> Li1-x CoO2 +
Li+(solvent) + Xe– 2Li + 3SOCl2 -> LiCl +
S + SO2
– 2Li + 2SO2 -> Li2S2O4
http://auto.howstuffworks.com/li
thium-ion-battery1.htm
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More on Li Batteries
• Li+ flows from source
in anode to cathode
during use
• Since anode and
cathode can hold Li+,
the battery is
rechargeable
• Ignite!
References
• Atkins, P.; Overton, T.; Rourke, J.; Weller, M.;
Armstrong, F. Inorganic Chemistry Fourth Edition;
W.H. Freeman and Company: New York, NY, 2006; pp.
258-271.
• Encyclopedia of Inorganic Chemistry; King, R.B.; John
Wiley and Sons: New York, NY, 1994; Vol 1, pp. 36-38.
• Group 1-The Alkali Metals.
http://www.chemsoc.org/visElements/pages/data/int
ro_groupi_data.html (accessed 3/14/07).
• Voet, D.; Voet, J.G.; Pratt, C.W. Fundamentals of
Biochemistry Second Edition; John Wiley and Sons:
United States, 2006; pp 303-305.
• How Lithium Batteries Work.
http://auto.howstuffworks.com/lithium-ionbattery1.htm ( accessed 4/8/07).
http://auto.howstuffworks.com/lithium-ion-battery1.htm
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